Sprecher + Schuh 31133 AMBUS EasySwitch 3-Pole Midget Fuse Block with LED Blown Fuse Indicator
Sprecher + SchuhThe Sprecher + Schuh 31133 is a three-pole AMBUS® EasySwitch DIN-rail mounted fuse block designed for Midget (1-1/2 × 13/32 in.) fuses, supplied by Wöhner as part of Sprecher + Schuh's circuit protection portfolio. Purpose-built for control and power circuit applications, the 31133 combines IP2 dead-front, touch-safe construction with a built-in LED blown fuse indicator — eliminating the guesswork and downtime associated with conventional open fuse blocks.
Unlike traditional open fuse blocks that expose live clips during servicing, the AMBUS enclosed design isolates fuse contacts from line power the moment the levered front compartment is opened. For electrical panels in demanding manufacturing and industrial environments, this translates to safer fuse changeouts, reduced arc flash risk, and measurable time savings during maintenance.
The 31133's LED indicator illuminates when a fuse opens in a live, energized circuit, allowing maintenance personnel to identify a blown fuse at a glance — no test equipment required. The compact 18mm-wide three-pole body saves up to 15% in panel space compared to conventional open fuse blocks, and the DIN-rail snap-in mounting eliminates additional hardware and speeds panel assembly. Wire terminals accept multiple conductor gauges, and UL 508 comb bus bars (sold separately) allow fast power distribution across multiple fuse blocks simultaneously.
The 31133 is the direct replacement for the legacy Sprecher + Schuh FH8-3PM30-L and is sold in packages of four. Common applications include transformer secondary protection, supplemental protection of control circuits, solenoids, and lighting circuits.
- catalog_number:
- 31133
- series:
- AMBUS EasySwitch
- manufacturer:
- Wohner (distributed by Sprecher + Schuh)
- legacy_catalog_number:
- FH8-3PM30-L
- fuse_type:
- Midget (1-1/2 x 13/32 in.)
- number_of_poles:
- 3
- voltage_rating:
- 600V AC/DC
- maximum_current:
- 30A
- led_blown_fuse_indicator:
- Yes
- led_indicator_working_voltage:
- 110...600V AC/DC
- led_indicator_leakage_current:
- 2 mA
- withstand_rating:
- 50 kA
- mounting:
- DIN-rail (Top Hat, low or high profile)
- enclosure_protection:
- IP2 dead-front (IEC/DIN)
- contact_material:
- Silver (Ag)
- body_material:
- Polyamide
- operating_temperature:
- -20...+55°C (-4...+130°F)
- wire_range_single:
- No. 18...4 AWG (0.75...25 mm²)
- wire_range_dual:
- No. 18...8 AWG (0.75...10 mm²) both wires must be same size
- wire_strip_length:
- 11 mm (0.43 in.)
- tightening_torque_18_to_8awg:
- 22 lb·in
- tightening_torque_6_to_4awg:
- 26 lb·in
- tightening_torque_metric:
- 2.5 N·m
- width:
- 54 mm (2.13 in.)
- height:
- 64 mm (2.51 in.)
- depth:
- 81 mm (3.19 in.)
- approvals:
- cULus Listed (UL File E230163), CSA Approved (CSA 110285), CE Marked
- compatible_bus_bars:
- 31549 (3-phase pin style, sold separately)
- compatible_end_anchors:
- V7-EA35 (normal duty), V7-EAH35 (heavy duty)
- common_applications:
- Transformer secondary protection
- replaces:
- FH8-3PM30-L
